In recent years, for example, for the purpose of environmental conservation, an electric motorcycle including as a driving power source an electric motor which is activated by electric energy stored in a battery has been developed (see, e.g., Patent Literature 1). In such an electric motorcycle, typically, a secondary battery which is capable of storing DC power therein is used, and an AC motor is used as an electric motor. In addition, the electric motorcycle incorporates an inverter for converting the DC power stored in the battery into AC power.